scholarly journals Effects of heat treatment systems on the physical properties of coated Scots pine (Pinus sylvestris L.) and poplar (Populus euramericana)

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 2708-2720 ◽  
Author(s):  
Ahmet Can
Keyword(s):  
Heat Treatment ◽  
Pinus Sylvestris ◽  
Physical Properties ◽  
Mass Loss ◽  
Scots Pine ◽  
Wood Species ◽  
Color Change ◽  
Vacuum Heat Treatment ◽  
Populus Euramericana ◽  
Water Based

Heat treatment is an environmentally friendly and efficient way to improve the properties of wood species. These treatments alter the substrates and can influence the surface properties of the varnish coatings. This paper investigated the effects of heat treatment on the physical properties of open and close systems Scots pine (Pinus sylvestris L.) and poplar (Populus euramericana) wood, coated with water-based, polyurethane-based, and oil/wax-based varnishes. Heat treatment was applied at the temperatures of 190, 212 °C for pine and 180, 200 °C for poplar, respectively. Color, gloss, and roughness tests were carried out for each of the coatings. Higher mass loss occurred in pine samples with heat treatment as compared to vacuum-heat treatment. Gloss decreased in OIL+WAX treatment and color change increased after the heat treatment, but these results were inhibited with vacuum-heat treatment. Maximum roughness was obtained in PUR varnishes and minimum roughness in OIL + WAX samples. The low roughness values provide some advantages in application.

scholarly journals Vacuum-heat treatment of Scots pine (Pinus sylvestris L.) wood pretreated with propanetriol

2020 ◽  
pp. 1-9
Author(s):  
Hüseyin Sivrikaya ◽  
Reza Hosseinpourpia ◽  
Sheikh Ali Ahmed ◽  
Stergios Adamopoulos
Keyword(s):  
Heat Treatment ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Vacuum Heat Treatment

scholarly journals COLOR CHANGE — MASS LOSS CORRELATION FOR HEAT-TREATED WOOD

2014 ◽  
Vol 2 ◽  
pp. 345-352 ◽  
Author(s):  
Cristina Marinela Olarescu ◽  
Mihaela Campean
Keyword(s):  
Heat Treatment ◽  
Mass Loss ◽  
Color Change ◽  
Treated Wood ◽  
Untreated Wood ◽  
Cost Effective ◽  
Assessment Procedure ◽  
Mathematical Correlation ◽  
Heat Treated ◽  
Two Parameters

Heat treatment is renowned as the most environmentally friendly process of dimensional stabilization that can be applied to wood, in order to make it suitable for outdoor uses. It also darkens wood color and improves wood durability. The intensity of heat treatment can be appreciated by means of two parameters: the color change occured in wood due to the high temperature, and the mass loss, which is a measure of the degree of thermal degradation. In order to find a mathematical correlation between these two parameters, an experimental study was conducted with four European wood species, which were heat-treated at 180°C and 200ºC, for 1-3 hours, under atmosheric pressure.The paper presents the results concerning the color changes and mass losses recorded for the heat-treated wood samples compared to untreated wood.  For all four species, the dependency between the color change and the mass loss was found to be best described by a logarithmic regression equation with R2 of 0.93 to 0.99 for the soft species (spruce, pine and lime), and R2 of 0.77 for beech. The results of this study envisage to simplify the assessment procedure of the heat treatment efficiency, by only measuring the color – a feature that is both convenient and cost-effective. 

Knotwood as a window to the indirect measurement of the decay resistance of Scots pine heartwood

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 600-604 ◽  
Author(s):  
Outi Karppanen ◽  
Martti Venäläinen ◽  
Anni M. Harju ◽  
Stefan Willför ◽  
Suvi Pietarinen ◽  
...  
Keyword(s):  
Pinus Sylvestris ◽  
Mass Loss ◽  
Scots Pine ◽  
Total Phenolics ◽  
Decay Resistance ◽  
Indirect Measurement ◽  
The Other ◽  
Extractive Content ◽  
Standing Trees ◽  
Further Development

Abstract There is wide variation in the extractive content and decay resistance of Scots pine (Pinus sylvestris L.) heartwood. The heartwood is not visible in standing trees and only poorly visible in timber. Therefore, it is difficult to identify extractive-rich trees, and consequently the most decay-resistant heartwood. On the other hand, knots are clearly visible in standing trees and timber. In the present paper we studied the possibility of measuring the decay resistance of Scots pine heartwood indirectly on the basis of the extractive concentration of knotwood. The material investigated consisted of 40 felled trees with a wide between-tree variation for extractive content and decay resistance of their heartwood. The extractive content of knotwood was found to be four- to five-fold higher than that of heartwood. Statistically significant correlations were found between the mass loss of heartwood and the concentrations of total phenolics and stilbenes in knotwood (r=-0.54, P<0.001 and r=-0.40, P=0.011, respectively), and for the concentration of total phenolics (r=0.42, P=0.008) and stilbenes (r=0.39, P=0.012) between heartwood and knotwood. We suggest further development of this technique in the context of rapid industrial screening of durable pine heartwood.

Mass loss and moisture dynamics of Scots pine (Pinus sylvestris L.) exposed outdoors above ground in Sweden

Holzforschung ◽  
2005 ◽  
Vol 59 (2) ◽  
pp. 183-189 ◽  
Author(s):  
Åsa Rydell ◽  
Mikael Bergström ◽  
Torbjörn Elowson
Keyword(s):  
Moisture Content ◽  
Pinus Sylvestris ◽  
Mass Loss ◽  
Scots Pine ◽  
Annual Ring ◽  
Water Storage ◽  
Ring Width ◽  
Moisture Uptake ◽  
Annual Ring Width ◽  
Moisture Dynamics

Abstract The durability of 566 Scots pine (Pinus sylvestris) samples was tested during a period of 9 years of exposure to weather in Sweden. The parameters investigated were heartwood/sapwood, origin, surface treatment, end-seal, storage and drying method, annual ring width and density. The weight was measured on 67 occasions during 9 years in order to assess the moisture content of the samples. The mass loss was determined for each sample at the end of the trial. Sapwood had a higher moisture uptake and a higher mass loss compared with heartwood. Even if sapwood was painted with an impermeable paint and then end-sealed, it still had higher average moisture content than heartwood. The results also demonstrated that sapwood was more sensitive to different handling conditions than heartwood. Sapwood was sensitive to air-drying and water storage, which was evident in the higher moisture uptake. In terms of mass loss, some differences were evident but they were not statistically significant due to the large standard deviation of the sapwood samples from water-stored logs. The only positive influence of water storage was on samples end-dipped in oil. One explanation could be that water storage led to increased permeability due to bacterial attack, which in turn enhanced the penetration of the oil. Heartwood had low and stable moisture dynamics during the test period, almost independent of treatment or handling conditions. No correlation with moisture uptake or mass loss was evident among annual ring width, origin or density.

Microstructure and stiffness of Scots pine (Pinus sylvestris L) sapwood degraded by Gloeophyllum trabeum and Trametes versicolor – Part I: Changes in chemical composition, density and equilibrium moisture content

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Thomas K. Bader ◽  
Karin Hofstetter ◽  
Gry Alfredsen ◽  
Susanne Bollmus
Keyword(s):  
Moisture Content ◽  
Pinus Sylvestris ◽  
Mass Loss ◽  
Sample Size ◽  
Equilibrium Moisture Content ◽  
Scots Pine ◽  
Trametes Versicolor ◽  
Mass Density ◽  
Gloeophyllum Trabeum ◽  
Physical And Chemical

Abstract Fungal degradation alters the microstructure of wood and its physical and chemical properties are also changed. While these changes are well investigated as a function of mass loss, mass density loss and changes in equilibrium moisture content are not well elucidated. The physical and chemical alterations are crucial when linking microstructural characteristics with macroscopic mechanical properties. In the present article, a consistent set of physical, chemical and mechanical characteristics is presented, which were measured on the same sample before and after fungal degradation. In the first part of this two-part contribution, elucidating microstructure/stiffness-relationships of degraded wood, changes in physical and chemical data are presented, which were collected from specimens of Scots pine (Pinus sylvestris) sapwood degraded by Gloeophyllum trabeum (brown rot) and Trametes versicolor (white rot) for up to 28 weeks degradation time. A comparison of mass loss with corresponding mass density loss demonstrated that mass loss entails two effects: firstly, a decrease in sample size (more pronounced for G. trabeum), and secondly, a decrease of mass density within the sample (more pronounced for T. versicolor). These two concurrent effects are interrelated with sample size and shape. Hemicelluloses and cellulose are degraded by G. trabeum, while T. versicolor was additionally able to degrade lignin. In particular because of the breakdown of hemicelluloses and paracrystalline parts of cellulose, the equilibrium moisture content of degraded samples is lower than that in the initial state.

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